That is from Tech Crunch, and it reminds us how context-dependent successful innovation can be. Just a modest change in the context can make all the difference between failure (or muddling along) and rapid adoption. The full post is worth reading.
Some apps wander around the wilderness for a while until they can find the perfect home. For Evernote, that home is the iPhone. The note-taking, picture-capturing, voice-recording, handwriting-recognizing universal memory service has been under development for years and launched last February in private beta on the PC. But it wasn't until May 29 that it debuted on the iTunes store as an iPhone app. That's when it started to take off.